find conflicting file names between two folders. For use with JS-style import systems. (I didn't want to just delete this, so it's here for posterity)

find_conflicts.py

#!/usr/bin/env python3
"""
Find conflicting files between folders.

When using absolute imports, it is possible to have conflicts where a module
is shadowed by a dependency in node_modules. This will detect such an issue
and warn. We compare without file extensions, to behave as Node imports do.
"""
import argparse
from pathlib import Path
import sys
from typing import Set

parser = argparse.ArgumentParser(
    description="given directories, find duplicate files/folders, ignoring their extensions"
)
parser.add_argument("dir", nargs="*", help="directories to compare")

def find_names(dir: str) -> Set[str]:
    """Normalize files and dirs, removing their extensions"""
    return set(f.stem for f in Path(dir).iterdir())

if __name__ == '__main__':
    args = parser.parse_args()
    problems: Set[str] = set()
    total: Set[str] = set()
    for dirname in args.dir:
        new = find_names(dirname)
        # see if our new file stems are in the running total and store them with any
        # existing problems
        problems = problems | (total & new)
        total = total.union(new)

    if len(problems) > 0:
        print(
            "Conflicting file(s) found. Try moving your file to a different namespace:",
            file=sys.stderr,
        )
        for filename in problems:
            print(filename, file=sys.stderr)
        sys.exit(1)